Swallowing disorders (dysphagia) and associated risks have increased in young children. Videofluoroscopic swallowing studies (VFSS), the primary method used to evaluate dysphagia, are increasingly performed in bottle-fed children. However, there are no standardized approaches to characterize the type and severity of the swallowing impairment. The goal of this project is to develop and test a standardized measurement tool and scoring schema for the quantification of swallowing impairment in bottle-fed children. In Aim 1, we will empirically reduce components for the tool into a reliable, parsimonious, and clinically relevant set based on measures of rater reliability and factor analysis from the scoring of 300 VFSS exams by trained speech-language pathologists (SLPs) at two clinical sites. We hypothesize at least 80% reliability within and between SLPs and the final set of components will be distributed into five functional domains. In Aim 2, we will establish the construct validity of the components within each domain by characterizing the relationship between component scores on the tool and external indicators of health, development, and well-being. We hypothesize that higher scores on the tool (poorer swallowing function), will be associated with poorer indicators of health, development, and well-being. In Aim 3, we will measure changes in physiologic swallowing impairment scores when different liquid consistencies are introduced during the VFSS. We hypothesize impairment scores will differ between consistencies. These studies will help develop a clinically practical, reliable, and valid standardized tool for assessing, measuring, and reporting physiologic swallowing impairment in bottle-fed children, ultimately resulting in improved diagnosis and management of children with this condition. PUBLIC HEALTH AND SAFETY RELEVANCE: Swallowing dysfunction is increasingly common in young children and associated with significant consequences. This study will help to improve the diagnosis, care, and outcomes of affected children by: (1) providing a basis for characterizing and tracking the natural history of swallowing impairments, (2) providing outcome measures for interventions for dysphagia, and (3) serving as biomarkers for clinical trials with children diagnosed with specific diagnostic conditions associated with dysphagia. The standardized, reliable, and validated tool will be available for immediate dissemination through web-based training modules.